After exiting SEB & force-quitting it (b/c it doesn't work when you restart), screenshots are disabled. System Preferences show that none of the settings are unchecked (cmd-shift-3 & 4). Running Lion v10.7.5
Sorry, I don't understand what you're writing. Currently SEB is only setting a flag on its browser windows, but this unfortunately just stops a screen shot of the window with cmd-shift-4, space, mouse click, not with cmd-shift-3.
I also never have found any settings for cmd-shift-3&4 in System Preferences. Where do you see that exactly?
In SEB 2.0 there should finally be a way to stop screen shots with cmd-shift-3 & 4 and even third party tools (but it's not yet implemented in the preview version pre1).
Never got answer. Older versions of SEB didn't stop screenshots. Only the new SEB 2.0 for Mac OS X does that.